Answer:
either a or c
Step-by-step explanation:
im sorry if they are both incorrect
There would be 12 people at the party!
In general, with n+1 people, the number of handshakes is the sum of the first n consecutive numbers: 1+2+3+ ... + n.
Since this sum is n(n+1)/2, we need to solve the equation n(n+1)/2 = 66.
This is the quadratic equation n2+ n -132 = 0. Solving for n, we obtain 11 as the answer and deduce that there were 12 people at the party.
Since 66 is a relatively small number, you can also solve this problem with a hand calculator. Add 1 + 2 = + 3 = +... etc. until the total is 66. The last number that you entered (11) is n.
Hope this helps!
11 by 16
Explanation:
Set up two equations
2
x
+
2
y
=
54
x
×
y
=
176
Solving the first equation for x
2
x
+
2
y
−
2
y
=
54
−
2
y
this gives
2
x
=
54
−
2
y
Divide both sides by 2
(
2
x
2
)
=
54
−
2
y
2
This gives.
x
=
27
−
y
putting this value into the second equation gives.
(
27
−
y
)
×
y
=
176
multiplying across the parenthesis gives
27
y
−
y
2
=
176
subtracting 176 from both sides gives
is
27
y
−
y
2
−
176
=
0
multiplying by negative one gives
−
27
y
+
y
2
+
176
=
0
factoring this into y gives
(
y
−
11
)
×
(
y
−
16
)
=
0
Solving for both y's gives
y
=
11
,
y
=
16
Answer:
D.) 1/4
Step-by-step explanation:
6/9 x 3/8
6(3) /8(9)
= 18/72
18/18=1
72/18=4
= D.) 1/4
A lot who carries nickels
